“The robots will be monitored by a person who will travel along with the robot.”
Why do the robot if it needs human supervision? One delivery person would be more efficient.
“Why do the robot if it needs human supervision?”
Pilot program, required by law.
Because state law bans any autonomous vehicles without a human supervisor with it? At this stage of development, vehicle AI isn’t very good and the chances of it running amok left to its own devices is high.
Not unlike how many states required early automobiles to be preceded and trailed by a flagman to warn others that the four wheeled fragmentation bomb was coming. (Think early steam cars which had a distressing tendency to literally explode.)